
/*!
 * Crypto-JS v1.1.0
 * http://code.google.com/p/crypto-js/
 * Copyright (c) 2009, Jeff Mott. All rights reserved.
 * http://code.google.com/p/crypto-js/wiki/License
 */

const Crypto = {};

(function() {
  var base64map = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'

  // Crypto utilities
  var util = Crypto.util = {
    // Bit-wise rotate left
    rotl: function(n, b) {
      return (n << b) | (n >>> (32 - b))
    },

    // Bit-wise rotate right
    rotr: function(n, b) {
      return (n << (32 - b)) | (n >>> b)
    },

    // Swap big-endian to little-endian and vice versa
    endian: function(n) {
      // If number given, swap endian
      if (n.constructor === Number) {
        return util.rotl(n, 8) & 0x00FF00FF | util.rotl(n, 24) & 0xFF00FF00
      }

      // Else, assume array and swap all items
      for (var i = 0; i < n.length; i++) { n[i] = util.endian(n[i]) }
      return n
    },

    // Generate an array of any length of random bytes
    randomBytes: function(n) {
      for (var bytes = []; n > 0; n--) { bytes.push(Math.floor(Math.random() * 256)) }
      return bytes
    },

    // Convert a string to a byte array
    stringToBytes: function(str) {
      var bytes = []
      for (var i = 0; i < str.length; i++) { bytes.push(str.charCodeAt(i)) }
      return bytes
    },

    // Convert a byte array to a string
    bytesToString: function(bytes) {
      var str = []
      for (var i = 0; i < bytes.length; i++) { str.push(String.fromCharCode(bytes[i])) }
      return str.join('')
    },

    // Convert a string to big-endian 32-bit words
    stringToWords: function(str) {
      var words = []
      for (var c = 0, b = 0; c < str.length; c++, b += 8) { words[b >>> 5] |= str.charCodeAt(c) << (24 - b % 32) }
      return words
    },

    // Convert a byte array to big-endian 32-bits words
    bytesToWords: function(bytes) {
      var words = []
      for (var i = 0, b = 0; i < bytes.length; i++, b += 8) { words[b >>> 5] |= bytes[i] << (24 - b % 32) }
      return words
    },

    // Convert big-endian 32-bit words to a byte array
    wordsToBytes: function(words) {
      var bytes = []
      for (var b = 0; b < words.length * 32; b += 8) { bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF) }
      return bytes
    },

    // Convert a byte array to a hex string
    bytesToHex: function(bytes) {
      var hex = []
      for (var i = 0; i < bytes.length; i++) {
        hex.push((bytes[i] >>> 4).toString(16))
        hex.push((bytes[i] & 0xF).toString(16))
      }
      return hex.join('')
    },

    // Convert a hex string to a byte array
    hexToBytes: function(hex) {
      var bytes = []
      for (var c = 0; c < hex.length; c += 2) { bytes.push(parseInt(hex.substr(c, 2), 16)) }
      return bytes
    },

    // Convert a byte array to a base-64 string
    bytesToBase64: function(bytes) {
      // Use browser-native function if it exists
      if (typeof btoa === 'function') return btoa(util.bytesToString(bytes))

      var base64 = []
      var overflow

      for (var i = 0; i < bytes.length; i++) {
        switch (i % 3) {
          case 0:
            base64.push(base64map.charAt(bytes[i] >>> 2))
            overflow = (bytes[i] & 0x3) << 4
            break
          case 1:
            base64.push(base64map.charAt(overflow | (bytes[i] >>> 4)))
            overflow = (bytes[i] & 0xF) << 2
            break
          case 2:
            base64.push(base64map.charAt(overflow | (bytes[i] >>> 6)))
            base64.push(base64map.charAt(bytes[i] & 0x3F))
            overflow = -1
        }
      }

      // Encode overflow bits, if there are any
      if (overflow !== undefined && overflow !== -1) { base64.push(base64map.charAt(overflow)) }

      // Add padding
      while (base64.length % 4 !== 0) base64.push('=')

      return base64.join('')
    },

    // Convert a base-64 string to a byte array
    base64ToBytes: function(base64) {
      // Use browser-native function if it exists
      if (typeof atob === 'function') {
        return util.stringToBytes(atob(base64))
      }

      // Remove non-base-64 characters
      base64 = base64.replace(/[^A-Z0-9+\/]/ig, '')

      var bytes = []
      for (var i = 0; i < base64.length; i++) {
        switch (i % 4) {
          case 1:
            bytes.push((base64map.indexOf(base64.charAt(i - 1)) << 2) |
              (base64map.indexOf(base64.charAt(i)) >>> 4))
            break
          case 2:
            bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0xF) << 4) |
              (base64map.indexOf(base64.charAt(i)) >>> 2))
            break
          case 3:
            bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0x3) << 6) |
              (base64map.indexOf(base64.charAt(i))))
            break
        }
      }

      return bytes
    }

  }

  // Crypto mode namespace
  Crypto.mode = {}
})()

module.exports = Crypto

// // 向左位移
// export function rotl(n, b) {
//   return (n << b) | (n >>> (32 - b))
// }

// // 向右位移
// export function rotr(n, b) {
//   return (n << (32 - b)) | (n >>> b)
// }

// export function bytesToHex(bytes) {
//   var hex = []
//   for (var i = 0; i < bytes.length; i++) {
//     hex.push((bytes[i] >>> 4).toString(16))
//     hex.push((bytes[i] & 0xF).toString(16))
//   }
//   return hex.join('')
// }

// export function stringToBytes(str) {
//   var bytes = []
//   for (var i = 0; i < str.length; i++) { bytes.push(str.charCodeAt(i)) }
//   return bytes
// }

// export function bytesToString(bytes) {
//   var str = []
//   for (var i = 0; i < bytes.length; i++) {
//     str.push(String.fromCharCode(bytes[i]))
//   }
//   return str.join('')
// }

// export function hmac(hasher, message, key, options) {
//   key = key.length > hasher._blocksize * 4
//     ? hasher(key, { asBytes: true })
//     : stringToBytes(key)
//   var okey = key
//   var ikey = key.slice(0)
//   for (var i = 0; i < hasher._blocksize * 4; i++) {
//     okey[i] ^= 0x5C
//     ikey[i] ^= 0x36
//   }

//   var hmacbytes = hasher(bytesToString(okey) + hasher(bytesToString(ikey) + message, { asString: true }), { asBytes: true })
//   return options && options.asBytes ? hmacbytes : options && options.asString ? bytesToString(hmacbytes) : bytesToHex(hmacbytes)
// }
